U.S. Pat. No. 6,253,166 entitled “Stable Algorithm for Estimating Airdata from Flush Surface Pressure Measurements” by Stephen A. Whitmore et al. describes a flush air data sensing (FADS) system for estimating air data using nonintrusive surface pressure measurements from a vehicle surface. U.S. Pat. No. 6,253,166 describes transforming an air flow model by strategically taking differences from outputs of three surface pressure sensors, known as triples. This triples formulation is then used to estimate and compute air data for air surrounding a flight vehicle from the surface pressure measurements. Accurate air data (e.g., Mach number, dynamic pressure, angle of attack, angle of sideslip, surface winds, airspeed, altitude, etc.) can help ensure efficient and safe flight. U.S. Pat. No. 6,253,166 describes six sensors located on a nose of a flight vehicle. An angle of attack is decoupled from an angle of sideslip by using specific locations of pressure sensors aligned along the vertical meridian of the nose.
A paper entitled “Simulation of a Flush Air-Data System for Transatmospheric Vehicles” in the Journal of Spacecraft and Rockets, Vol. 45, No. 4, July-August 2008, by Joel C. Ellsworth et al. describes a FADS system based on the X-34 outer mold line.
A paper entitled “Mars Entry Atmospheric Data System Trajectory Reconstruction Algorithms and Flight Results” by Christopher D. Karlgaard et al. from the 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition on Jan. 7-10, 2013 describes a system of seven pressure transducers linked to ports on the entry vehicle forebody to record pressure distribution during atmospheric entry. The measured surface pressures are used to generate estimates of atmospheric quantities based on modeled surface pressure distributions.
A paper entitled “Flush Airdata Sensing (FADS) System Calibration Procedures and Results for Blunt Forebodies,” by Brent R. Cobleigh et al., American Institute of Aeronautics and Astronautics, Inc., 1999, describes using blunt-forebody pressure data to study behavior of NASA Dryden Flight Research Center FADS pressure model and solution algorithm.
A paper entitled “Comparing Three Algorithms for Modeling Flush Air Data Systems” by Susanne Weiss from the 40th AIAA Aerospace Sciences Meeting and Exhibit on Jan. 14-17, 2002 describes a FADS system mounted on a modified centerline tank of an F-4 Phantom. This document compares a weighted least squares solution to a triples-based solution and a five-hole probe method. The contents of the foregoing documents are hereby incorporated by reference herein in their entireties.